This invention relates to stabilizing the activity of enzyme compositions and, more particularly, to stabilizing enzyme-containing compositions derived from so-called gullets of milk-fed animals.
One well recognized method for preserving enzyme-containing compositions against loss of activity during storage is to dry the composition. U.S. Pat. No. 2,794,743 describes an enzyme-containing composition in dry powder form prepared by grinding the edible tissue from between the tongue and trachea of young ruminants, such as calves, kids and lambs. Although dried to a low moisture content, such compositions have been found to lose their lipolytic activity during storage even though stored under refrigeration. Over a period of several weeks, dried enzyme-containing compositions made from calf tissue can lose up to as much as 40% of their initial activity. Dried enzyme-containing compositions made from kid and lamb tissue are also relatively unstable, although less unstable than those made from calf tissue.
The above enzyme-containing compositions are added to cheeses to promote ripening or aging and thereby produce desirable flavor and body consistency characteristics. The flavor and/or body consistency of some cheeses, particularly rapidly ripening cheddar cheeses, is highly dependent on the lipolytic activity of the enzyme-containing composition. In the production of such cheeses, a cheese maker typically assays a batch of the enzyme-containing composition and, based on the measured activity, determines the quantity of the enzyme-containing composition required for a given amount of cheese to produce the desired flavor and body consistency. The cheese maker thereafter continues to use the same amount of the enzyme-containing composition for the entire batch. A significant loss in the lipolytic activity over the period of time a batch of the enzyme-containing composition is being used can produce an unacceptable change in the flavor and/or body consistency of the final cheese product.
The loss of lipolytic acitivity can be minimized by vacuum packing the enzyme-containing composition. In addition to the added cost for packaging, the enzyme-containing composition tends to rapidly lose its activity upon opening of the package. This may not be particularly disadvantageous for applications where the enzyme-containing composition is used immediately after the package is opened. However, for applications requiring the enzyme-containing composition to be formulated with other materials prior to use or for operations where it takes several weeks to use up a batch of the enzyme-containing composition, the loss of activity during the time from package opening to actual use can create the above-mentioned problem.